Enable will stay in training next year and be aimed at a historic third win in the Prix de l'Arc de Triomphe.
Ridden by Frankie Dettori for trainer John Gosden, the four-year-old filly won Europe's most valuable horse race for a second time at Longchamp in October.
She followed up with victory in the Breeders' Cup Turf in the United States.
No horse has ever won the Arc more than two times.
"We are pleased to announce that dual Arc winner and recent Breeders' Cup heroine Enable will stay in training for 2019," said a spokesperson for owner Khalid Abdullah's Juddmonte Farms operation.
"A third Arc will be her main target."
BBC horse racing correspondent Cornelius Lysaght
This is clearly very good news. To have become the first horse to complete that double in two of the world's greatest races - maybe THE greatest races - makes Enable a genuine international superstar. And, as the old cliche goes, every sport needs its stars…
All involved had said they would do the best thing for the filly, who after a busy three-year-old career had just the three starts in 2018 because of injury.
Though the hope was that might mean another season racing, there was always the thought that Juddmonte is a highly successful commercial breeding operation, so producing 'little Enables' might have been too hard to resist.
That'll still happen, just later.